Aminoacyl tRNA Synthetase

Somanna A. N.

Fig: 2 steps of aminoacyl tRNA charging. (a) Adenylylation of amino acid (b) Transfer of adenylylated amino acid to tRNA

tRNA charging

Classes of Aminoacyl tRNA Synthetases

Structure of tRNA: Elements required for aminoacyl synthetase recognition

Co-crystal structure of glutaminyl aminoacyl tRNA synthetase with tRNA-Glu

Enzyme is shown in grey and tRNA in purple. The yellow, red and green is Glutaminyl AMP

Distinguishing features of similar amino acid

Accuracy of Aminoacyl tRNA formation

Proofreading

Editing of Aminoacyl-tRNA. The flexible arm of an aminoacyl-tRNA can move the amino acid between the activation site and the editing site. If the amino acid fits well into the editing site, the amino acid is removed by hydrolysis.

Cysteinyl tRNA charged with Cysteine or Alanine